use GovernanceInputFile
var cursor = db.getCollection('GovernanceInsightInputFile').find()
while (cursor.hasNext()) 
{
    var doc = cursor.next();
    db.getCollection('GovernanceInsightInputFile').update({_id : doc._id}, {$set : {CreationTimeStamp : new Date(doc.CreationTimeStamp)}})
}
db.getCollection('GovernanceInsightInputFile').update({}, {$unset: {MimeType:1}} , {multi: true})
db.getCollection('GovernanceInsightInputFile').update({}, {$unset: {FileContent:1}} , {multi: true})